text: Levobupivacaine has become a more favourable alternative for regional anaesthesia than bupivacaine due to its reduced toxicity. A plethora of non-human studies have established levobupivacaine’s lower risk of cardiac and neurotoxic adverse effects. Most animal studies show that the lethal dose (LD) of levobupivacaine is approximately 50% higher than that of bupivacaine. In general, laevorotatory isomers tend to cause significantly fewer adverse effects and are thus a safer pharmacological alternative. Levobupivacaine has a 97% protein binding rate which is 2% higher than what is observed in bupivacaine. The faster protein binding rate contributes to its reduced toxicity level.
  In human volunteer studies, levobupivacaine consistently proved to have a safety advantage over bupivacaine. Risk factors for local anaesthetic toxicity depend on the administration of levobupivacaine to myocardial and cerebral tissue, as well as the predisposition of these tissues to levobupivacaine’s negative effects. 
  Age is a relevant factor in vulnerability to levobupivacaine toxicity. Elderly patients are more likely to have pre-existing conditions impacting the cardiac, renal and hepatic systems, which contribute to the slower absorption rate and plasma concentrations below the toxic level compared to younger patients. On the other hand, homeostatic disbalance can exacerbate toxic effects.
  It is important to adjust the dosage of levobupivacaine in paediatric patients due to their underdeveloped metabolic processing to prevent reaching toxic levels. The dosage of local anaesthetics is calculated based on the patient’s weight and body mass index, however, the association power is stronger in children than in adults. Moreover, symptoms of systemic toxicity like paraesthesia are harder to notice in children.